In a large deep skillet or wide pot, heat the olive oil and butter over medium heat until the butter is melted.
Add the minced garlic and sauté for 1 to 2 minutes until fragrant but not browned.
Add the fettuccine pasta, vegetable broth, water, salt, and black pepper to the pot. Stir to combine and ensure the pasta is submerged in the liquid.
Bring the mixture to a boil over medium-high heat. Once boiling, reduce the heat to medium-low and simmer uncovered, stirring occasionally, until the pasta is tender and most of the liquid is absorbed, about 12 to 15 minutes.
Stir in the heavy cream, lemon zest, and lemon juice. Cook for an additional 2 to 3 minutes, stirring frequently, until the sauce thickens slightly.
Remove the pot from heat and stir in the grated Parmesan cheese until melted and creamy.
Taste and adjust seasoning with additional salt or lemon juice if desired.
Sprinkle the chopped fresh parsley over the pasta before serving.